Serum insulin levels and HOMA-IR values of CUG-SGA, NCUG-SGA rats and AGA rats.

<p>Appropriate for gestational age (AGA), small for gestational age with catch-up growth (CUG-SGA), small for gestational age with no catch-up growth (NCUG-SGA), homoeostasis model assessment for insulin resistance (HOMA-IR). *<i>P</i><0.05 CUG-SGA or NCUG-SGA <i>vs</i> AGA; ^#<i>P</i><0.05 CUG-SGA <i>vs</i> NCUG-SGA.</p

Anthropometric parameters of SGA and AGA groups.

<p>The ratioes of male to female in appropriate for gestational age (AGA), small for gestational age with catch-up growth (CUG-SGA) and small for gestational age with no catch-up growth (NCUG-SGA) groups were 26/30, 29/25 and 41/28. No significant differences were observed in the ratio of male to female among the three groups (p>0.05). *<i>P</i><0.05 CUG-SGA or NCUG-SGA <i>vs</i> AGA; ^#<i>P</i><0.05 CUG-SGA <i>vs</i> NCUG-SGA; Data are means±SD.</p

Immunoblot analysis of p-IRS-1, p-AKT, p-ERK and SOCS3 in skeletal muscle cell lysates from CUG-SGA, NCUG-SGA and AGA rats.

<p>Rats in appropriate for gestational age (AGA), small for gestational age with catch-up growth (CUG-SGA) and small for gestational age with no catch-up growth (NCUG-SGA) groups (n = 16 for each group) were either intraperitoneal injected intravenously with insulin (Ins) or saline (baseline control) at 4 weeks of age and the skeletal muscles were excised for examination of IRS-1, AKT, ERK, SOCS3 and the phosphorylation of IRS-1, AKT, ERK (p-IRS-1/p-AKT/p-ERK) via Immunoblot analysis. Activation of IRS-1, AKT and ERK were expressed as the ratio of p-IRS-1/p-AKT/p-ERK to total IRS-1, AKT and ERK, respectively. The level of SOCS3 was expressed as the ratio of SOCS3 to tubulin. Data were quantified from 16 samples and were presented as the mean ± SD. *<i>P</i><0.05 CUG-SGA or NCUG-SGA <i>vs</i> AGA; ^#<i>P</i><0.05 CUG-SGA <i>vs</i> NCUG-SGA.</p

Immunoblot analysis of p-IRS-1, p-AKT, p-ERK and SOCS3 in skeletal muscle cell lysates from CUG-SGA and AGA rats before and after GHR inhibition.

<p>Rats in the appropriate for gestational age (AGA) and small for gestational age with catch-up growth (CUG-SGA) groups (n = 16 per group) were further separated into three sub-groups. At four weeks of age, sub-group one received intraperitoneal injection of saline (control), sub-group two received insulin (Ins) stimulation and sub-group three received the GHR inhibitor Somavert before insulin stimulation. The skeletal muscle was then excised for examination of IRS-1, AKT, ERK, SOCS3, and the phosphorylation of IRS-1, AKT, ERK (p-IRS-1/p-AKT/p-ERK) via Immunoblot analysis. Activation of IRS-1, AKT and ERK were expressed as the ratio of p-IRS-1/p-AKT/p-ERK to total IRS-1, AKT and ERK, respectively. The level of SOCS3 was expressed as the ratio of SOCS3 to tubulin. Data were quantified from 16 samples and presented as the mean ± SD. *<i>P</i><0.05 Somavert(-)+Ins(+) or Somavert(+)+Ins(+) <i>vs</i> baseline; ^#<i>P</i><0.05 Somavert(-)+Ins(+) <i>vs</i> Somavert(+) +Ins(+); Δ<i>P</i><0.05 CUG-SGA <i>vs</i> AGA.</p

Crosstalk between insulin and GH signaling.

<p>GH signaling induces up-regulation of SOCS3 in SGA with Catch-up Growth. Higher SOCS3 levels result in impairment of IRS-1-PI3K-AKT signaling and it may have a role in insulin resistance.</p

Food intakes of the maternal and young rats in different groups.

<p>The numbers of rats in the maternal appropriate for gestational age (AGA), small for gestational age with catch-up growth (CUG-SGA) and small for gestational age with no catch-up growth (NCUG-SGA) groups were 15, 20 and 20, respectively. Young rats at 4 weeks: n = 56 in AGA group, n = 54 in CUG-SGA group, n = 69 in NCUG-SGA group. There are not significant differences in AGA, CUG-SGA and NCUG-SGA groups. Food intakes of young male rats in different groups were comparable to those of females respectively.</p